I'm thinking of buying a Canon 30D and 2 L series lenses from the US as the price is much better than the UK. I understand that I "may" need to pay duty (6% i think), plus VAT @17.5% IF the goods are picked up by customs. If this happens I'll still be better off than buying in the UK, so that's fine.

My question is - I'm travelling to New York in July with the camera gear, what is the situation when I return to the UK, as if I've not paid the duties and VAT, presumably I must go through the "goods to declare" channel ?

You may want to check with Canon in the UK to see if they will service a camera purchased in the U.S.

For example, I know that Nikon US will not service a camera intended for another market, even if you are willing to pay them for the service. Nikon Canada has the same policy.

Because you bypass the regional distributors when making this kind of purchase (for example, Nikon US, Nikon Canada, Nikon Europe), they don't make any profit on the sale, and as a result do not want to incur any cost of repairing the cameras.

They take it one step further to discourage gray market cameras (cameras intended for a different region), by refusing to service one, even if you are willing to pay them for the service.

Canon in the UK may (or may not) have a more liberal policy on the servicing of gray market cameras. But, I'd make sure to get it in writing that they will actually service a camera bought in another region before making this kind of purchase.

Otherwise, you may need to send it to the U.S. for any service issues.

u can bring £150 worth of stuff back from the USA, note thats in sterlin so it could be just short of $300 depending on exchange rate, which is pretty high at moment, not sure though if duty is payable on the extra or all on the price.